trigger: add "${tg_displayed}" in conditions of default trigger "beep"

The command of "beep" trigger is now executed only if the message is
displayed (not filtered with /filter).

ChangeLog.asciidoc

@@ -26,6 +26,7 @@ http://weechat.org/files/releasenotes/ReleaseNotes-devel.html[release notes]
 * irc: display own nick changes in server buffer (closes #188)
 * irc: disable creation of temporary servers by default with command /connect,
   new option irc.look.temporary_servers
+* trigger: add "${tg_displayed}" in conditions of default trigger "beep"
 * trigger: add option "restore" in command /trigger
 
 === Bugs fixed

ReleaseNotes.asciidoc

@@ -46,6 +46,17 @@ instead of milliseconds:
 * function 'util_timeval_add': the argument 'interval' is now expressed in
   microseconds.
 
+=== Default "beep" trigger
+
+The command of "beep" trigger is now executed only if the message is displayed
+(not filtered with /filter).
+
+You can restore the default "beep" trigger with the following command:
+
+----
+/trigger restore beep
+----
+
 === Default triggers for hiding passwords
 
 Triggers used to hide passwords have been fixed for *BSD operating systems.

src/plugins/trigger/trigger-config.c

@@ -53,7 +53,7 @@ char *trigger_config_default_list[][1 + TRIGGER_NUM_OPTIONS] =
     { "beep", "on",
       "print",
       "",
-      "${tg_highlight} || ${tg_msg_pv}",
+      "${tg_displayed) && (${tg_highlight} || ${tg_msg_pv})",
       "",
       "/print -beep",
       "ok" },